A plurality of testing devices, with which measuring devices are tested automatically for their ability to function properly, are known from the state of the art. Measuring devices are tested by an automatic or semiautomatic method by means of such testing devices in order to ensure that these are still fully functional and there are no safety hazards for the user.
Testing devices, in which portable gas-measuring devices are tested after their use or after the end of a specified time interval, are used especially in the area of portable gas-measuring devices, for example, in production plants in the chemical industry as well as refineries. It is essential here that the sensors used in the portable gas-measuring devices be tested for their ability to function and be calibrated when needed. If a corresponding gas sensor is no longer able to function and must be replaced, corresponding information is outputted via a display unit of the testing device. The components provided for generating an alarm are also likewise tested, as a rule, during a corresponding test.
Such a testing device for portable gas-measuring devices is known, for example, from DE 10 2012 210 090 B4. The testing device has a main unit including a control and analysis unit with a plurality of test modules connected to the main unit for data exchange. A gas-measuring device each can be inserted into a test module, the type of gas-measuring device being detected automatically and the test gas or test gases needed for this type of device being determined on the basis of the detected data. The main unit further has a plurality of gas inlets for different test gases, and the gas is sent to the test module via a gas line under control by the control and analysis unit. The testing device for portable gas-measuring devices specifically has a control and analysis unit, which is configured such that a detailed testing schedule is set up on the basis of the gas-measuring devices located in the testing devices, so that the testing can be carried out in a time-optimized manner in case of a plurality of mobile gas-measuring devices. This is especially significant because the individual gas-measuring devices are always equipped with the respective gas sensors needed based on the need and different test gases are needed for the testing of the different sensors and the duration of the testing of the individual gas-measuring devices may differ.
Further, a testing device for testing mobile gas-measuring devices, which can detect sensor poisonings in the gas-measuring devices in an especially suitable manner, is known from DE 10 2013 008 425 B3. The testing schedule needed for the testing of the individual gas-measuring devices inserted into the testing device is likewise also determined in this testing device on the basis of a corresponding system as well as of a central control and analysis unit. The testing device described is characterized, furthermore, in that a suitable quantity of a test gas is fed to the individual gas-measuring devices in a chronologically spaced manner, and the sensors being tested can be tested based on a comparison of the measured values obtained whether a sensor poisoning is present.
The concentrations of selected gases, which are present in the area surrounding the user of the portable gas-measuring device, who is potentially at risk, are tested with the portable gas-measuring devices, which are routinely tested with the above-described testing devices. Such portable gas-measuring devices therefore also have, in addition to the sensor system necessary for the determination of the gas concentration, suitable output units, which make it possible to generate an alarm for the user of a gas-measuring device. Such an alarm is usually generated both acoustically, optically and/or by touch. Since the portable gas-measuring devices described are frequently used in industrial plants, in which rather substantial noise is generated and/or the user of the device uses a protective device, which makes perception of acoustic signals difficult, modern portable measuring devices have, as a rule, vibration motors, which trigger a vibration alarm in case of an alarm and thus inform the user of the device of a potential hazard.
To also carry out the testing of the vibration motors in portable gas-measuring devices for their ability to function, the humming caused by the vibration was hitherto recorded with a microphone and analyzed during corresponding testing or the vibration activity was tested by means of acceleration sensors. Both of the above-mentioned methods are, however, unreliable and lead to high percentages of false positive or false negative test results.